The present invention relates to phase control devices in general and phase control devices as applied to phased array antennas in particular.
Phase control devices play an important role in radar and communications in general, and in satellite communications in particular. There are known in the art, planar phased array antennas for communicating with satellites which are mountable on moving platforms. For certain of such applications the planar phased array antenna may comprise several hundred radiating elements. This results in the use of a corresponding several hundred phase shifters, one for each radiating element. Owing to the large number of phase shifters required, the phased arrays themselves are therefore expensive.
There is, therefore, a need for reducing the number of phase shifters required for a given number of radiating elements of a phased array.
In the following description and claims reference is made to phase shifters and to phase control devices as applied to phased array antennas. This is done for clarity of illustration only and should in no way be interpreted as a limiting property of the phase control devices of the invention which can be utilized by any system having a plurality of input/output ports with signals requiring control of their relative phases.
In referring to phase shifters reference is implicitly made to the phase shift elements and switches constituting the phase shifters; hence reducing the number of phase shifters required for a given task implies reducing the number of constituent phase shift elements and switches.
It is an object of the present invention to provide a phase control device which reduces the number of phase shifters required in a given application as compared to prior art techniques. In addition to the reduction in the number of phase shift elements and switches, another object of the present invention is the simplification of the resulting architecture wherein the reduced number of phase shift elements is separated off from the reduced number of switches, a feature of significant importance in chip miniaturization.
In accordance with the present invention there is provided a phase control device for providing a plurality of phase values, comprising:
a plurality of electrically interconnected phase shift elements; and
a plurality of switches electrically interconnected by a plurality of first conducting lines and a plurality of second conducting lines, said plurality of switches electrically connected to said plurality of phase shift elements by means of said plurality of second conducting lines.
If desired the phase shift elements and the switches may be partitioned into phase control units, the phase shift elements in each phase control unit being electrically interconnected and the switches in each phase control unit being electrically interconnected, only to switches within the same phase control unit and to the phase shift elements thereof.
Further, if desired, all the phase control units are parallelly connected.
Optionally, all the phase control units are serially connected.
Alternatively, some of the phase control units are serially connected whereas others are parallelly connected.
Also, if desired, the phase control units may be connected to the switches of a further phase control unit.
In a specific application of the invention the phase shift elements, the switches and the first conducting lines are disposed on one side of a dielectric plate; whereas the second conducting lines are disposed on the opposite of said dielectric plate.
In accordance with one embodiment of the present invention the phase control device further comprises, in a piecewise layered formation, a plurality of dielectric plates, each having front and rear faces, and wherein said plurality of phase shift elements, said plurality of first conducting lines and said plurality of second conducting lines are disposed on the faces of said dielectric plates.
In accordance with one embodiment of the invention the phase shift elements are serially connected.
In accordance with another embodiment of the invention the phase shift elements are parallelly connected.